The reliability of the results from the research projects in this Center for Medical Countermeasures against Radiation depends upon the accurate delivery of the intended radiation dose to the target normal tissues. Comprehensive quality assurance (QA) procedures, accurate three dimensional (3D) dose calculations, and robust irradiation techniques are necessary to ensure high accuracy in the dose delivery. The overall function of the Irradiation Core is to provide safe and accurate delivery of radiation dose for the MCW-based research projects, and to document detailed information for each irradiation. Comprehensive QA procedures and documentation will be developed to ensure that our radiation facility is operated under the GLP (Good Laboratory Practices) or GLP-like standards. A full commissioning for our radiation devices and a treatment planning system will be performed. The procedures of daily, monthly and annual QA will be developed to routinely test the safety, mechanical and dosimetric aspects of the irradiation machines following the recommendations of the protocol commonly used for a clinical radiation therapy machine. The 3D dose calculation will be performed based on CT or MRI images using the treatment planning system or a Monte Carlo package. To facilitate different irradiations required by the three projects at MCW, a variety of radiation delivery techniques will be developed to ensure the delivery safety and accuracy under different irradiation scenarios, e.g., nuclear weapon vs nuclear contamination. The complete irradiation information will be documented on a chart to be created for each animal subject irradiated. The information in the chart along with the QA data will provide a complete picture for the irradiation, allowing absolute dose comparison between the results obtained by the consortium members. In summary, the goals of this project are to provide radiation dosimetry services to the MCW-based projects, and bring the irradiation facility up the standards required for studies that are to be submitted to the FDA.